Spongy degeneration of central nervous system

Spongy Degeneration of the Central Nervous System
Specialty	Neurology

Spongy degeneration of the central nervous system, also known as Canavan disease, is a rare inherited disorder that affects the brain and spinal cord. This condition is characterized by the degeneration of white matter in the brain and spinal cord, leading to a spongy degeneration. It is classified under leukodystrophy, which encompasses a group of disorders involving the degeneration of myelin, the protective covering of nerve fibers.

Symptoms

The symptoms of spongy degeneration typically begin in early infancy and may include poor head control, developmental delay, abnormally large head size (macrocephaly), and severe muscle weakness. As the disease progresses, affected individuals may experience feeding difficulties, seizures, and loss of motor skills.

Causes

Spongy degeneration is caused by mutations in the ASPA gene, which encodes the enzyme aspartoacylase. This enzyme is crucial for the breakdown of N-acetylaspartic acid (NAA) in the brain. Mutations in the ASPA gene lead to the accumulation of NAA, which is toxic to the brain's white matter, causing the characteristic spongy degeneration.

Diagnosis

Diagnosis of spongy degeneration is primarily based on clinical evaluation, magnetic resonance imaging (MRI), and genetic testing. MRI scans typically show diffuse white matter abnormalities in the brain, while genetic testing can confirm mutations in the ASPA gene.

Treatment

There is currently no cure for spongy degeneration of the central nervous system. Treatment is supportive and symptomatic, focusing on managing symptoms and improving quality of life. Therapies may include physical therapy, occupational therapy, and medications to control seizures and spasticity.

Prognosis

The prognosis for individuals with spongy degeneration is generally poor, with most affected children not surviving past childhood. However, the course of the disease can vary, and some individuals may live into adolescence or young adulthood.

Epidemiology

Spongy degeneration is a rare disorder, with a higher incidence in individuals of Ashkenazi Jewish descent due to a higher carrier rate of ASPA gene mutations in this population.